| 摘要 |
<p>A pumping assembly having a high-pressure pumping stage and an integrated transfer pumping stage. The pumping assembly comprises a cam (104;204) arranged for eccentric rotation about a drive shaft axis (A), a cam rider (106;206), a cam follower (112;212), the cam follower (112;212) having reciprocal movement parallel to a cam follower axis (Q) that is perpendicular to the drive shaft axis (A), a high-pressure pumping head having a high-pressure pumping chamber, and a pumping element driven by the cam follower (112;212). The pumping assembly further comprises a first chamber (150a;250a), inlet means (174;274) for allowing fluid flow into the first chamber (150a;250a), and outlet means (150b,163,166,166a;250b,263,266,266a) for receiving fluid from the first chamber (150a;250a) and for delivering fluid to the high-pressure pumping head. Rotation of the cam (104;204) about the driveshaft axis (A) causes an increase in volume of the first chamber (150a;250a) during a first part of the pumping cycle and a decrease in volume of the first chamber (150a;250a) during a second part of the pumping cycle, so as to effect a transfer pumping of fluid from the inlet means (174;274) to the outlet means (150b,163,166,166a;250b,263,266,266a) for delivery to the high-pressure pumping head.</p> |
